Microscopy-positive and drug-resistant pulmonary tuberculosis (MPT+) is one of the most feared diseases due to the cost of its management and the associated mortality. The GeneXpert, a new molecular test, is in greate...Microscopy-positive and drug-resistant pulmonary tuberculosis (MPT+) is one of the most feared diseases due to the cost of its management and the associated mortality. The GeneXpert, a new molecular test, is in greater demand for the diagnosis of MPT+ resistance cases. The application of GeneXpert to new cases of MPT+ is not effective in the country’s TB screening centres. The objective of this study is to assess the contribution of GeneXpert to the determination of MPT+ resistance cases in Bangui. The study was cross-sectional and covered the period from February to July 2022. The diagnosis of tuberculosis was first performed by microscopy with Ziehl Neelsen hot stain. The GeneXpert was then used to test for resistance in the sputum of all patients with positive microscopy. The collected data was entered into Excel 2013 and analysed with Epi Info 3.3.7. We analysed data from 755 patients, 80 of whom had resistance. The 80 patients ranged in age from 6 to 68 years (mean age = 35 years). The prevalence of resistant TB was 10.60% (80/755). Primary resistance accounted for 73.75% and secondary resistance for 26.25%. The age group 20 - 39 years (57.50%), male (72.50%), 8th district (17.50%), people living in couples (53.75%), farmers (13.75%) were the socio-demographic characteristics most affected by resistance. Treatment failure (13.75%), relapses (13.75%), the notion of contagion (28.75%), a history of smoking (40%) and alcohol (61.25%) were the clinical antecedents reported by the patients. Treatment failure and relapse were the variables associated with the occurrence of resistant PMT+ (p 0.05). A considerable proportion of the overall Mycobacterium tuberculosis resistance to anti-tuberculosis drugs (10.60%) was identified by GeneXpert. Treatment failure and relapse were the factors associated with the risk of resistance.展开更多
Detection of Mycobacterium tuberculosis complex (MTBC) in extrapulmonary specimens can be challenging due to their paucibacillary nature. This difficulty is especially true for cerebrospinal fluid (CSF), and the low s...Detection of Mycobacterium tuberculosis complex (MTBC) in extrapulmonary specimens can be challenging due to their paucibacillary nature. This difficulty is especially true for cerebrospinal fluid (CSF), and the low sensitivity and specificity for diagnosis hampers rapid detection and treatment in vulnerable populations. GeneXpert MTB/RIF Ultra has been shown to provide rapid results for detection of MTBC and associated Rifampin resistance, but there is limited data regarding standardized methods for CSF processing on this assay. In this study, we sought to provide guidance regarding the best methods for CSF processing, including optimal volumes to test, length of incubation with sample reagent and finally effects of long-term freezing on detection.展开更多
Objective A PCR-reverse dot blot hybridization （RDBH） assay was developed for rapid detection of rpoB gene mutations in ＇hot mutation region＇ of Mycobacterium tuberculosis （M. tuberculosis）. Methods 12 oligonucl...Objective A PCR-reverse dot blot hybridization （RDBH） assay was developed for rapid detection of rpoB gene mutations in ＇hot mutation region＇ of Mycobacterium tuberculosis （M. tuberculosis）. Methods 12 oligonucleotide probes based on the wild-type and mutant genotype rpoB sequences of M. tuberculosis were designed to screen the most frequent wild-type and mutant genotypes for diagnosing RIF resistance. 300 M. tuberculosis clinical isolates were detected by RDBH, conventional drug-susceptibility testing （DST） and DNA sequencing to evaluate the RDBH assay. Results The sensitivity and specificity of the RDBH assay were 91.2% （165/181） and 98.3% （117/119）, respectively, as compared to DST. When compared with DNA sequencing, the accuracy, positive predictive value （PPV） and negative predictive value （NPV） of the RDBH assay were 97.7% （293/300）, 98.2% （164/167）, and 97.0% （129/133）, respectively. Furthermore, the results indicated that the most common mutations were in codons 531 （48.6%）, 526 （25.4%）, 516 （8.8%）, and 511 （6.6%）, and the combinative mutation rate was 15 （8.3%）. One and two strains of insertion and deletion were found among all strains, respectively. Conclusion Our findings demonstrate that the RDBH assay is a rapid, simple and sensitive method for diagnosing RIF-resistant tuberculosis.展开更多
Objective:To identify the clinical,laboratory,and radiological markers that could predict a positive GeneXpert result in patients suspected of tuberculous meningitis.Methods:In this prospective,observational study,pat...Objective:To identify the clinical,laboratory,and radiological markers that could predict a positive GeneXpert result in patients suspected of tuberculous meningitis.Methods:In this prospective,observational study,patients with tuberculous meningitis were systematically evaluated.Various clinical,laboratory[including cerebrospinal fluid(CSF)microscopy,culture,and GeneXpert],and neuroimaging factors were examined.All participants were administered anti-tuberculous treatment and corticosteroids.A six-month follow-up was done to evaluate the outcome.Results:Of the 116 patients studied,54(46.6%)tested positive for GeneXpert,while 62(53.4%)were negative.Third cranial nerve involvement(OR 3.71,95%CI 1.052-13.09,P=0.04)and the presence of basal exudates on neuroimaging(OR 5.22,95%CI 2.03-13.42,P=0.001)emerged as independent predictive factors for a positive GeneXpert result.A positive CSF GeneXpert result(P=0.002)and drug resistance(P=0.004)were significantly linked to adverse outcomes.Additionally,a high score on the Medical Research Council stageⅢ(OR 5.64,95%CI 1.18-26.87,P=0.03)and elevated CSF cell counts(OR 1.002,95%CI 1.00-1.001,P=0.03)were identified as independent predictors of poor prognosis.Conclusions:Third cranial nerve involvement and the presence of basal exudates were significant indicators of a positive GeneXpert result.MRC stageⅢdisability and elevated CSF cell counts predicted poor outcomes.展开更多
Objective To detect the specific mutations in rpoB gene of Mycobacterium tuberculosis by oligonucleotide microarray. Methods Four wild-type and 8 mutant probes were used to detect rifampin resistant strains. Target DN...Objective To detect the specific mutations in rpoB gene of Mycobacterium tuberculosis by oligonucleotide microarray. Methods Four wild-type and 8 mutant probes were used to detect rifampin resistant strains. Target DNA of M. tuberculosis was amplified by PCR, hybridized and scanned. Direct sequencing was performed to verify the results of oligonucleotide microarray Results Of the 102 rifampin-resistant strains 98 （96.1%） had mutations in the rpoB genes. Conclusion Oligonucleotide microarray with mutation-specific probes is a reliable and useful tool for the rapid and accurate diagnosis of rifampin resistance in M. tuberculosis isolates.展开更多
<b><span style="font-family:Verdana;">Background:</span></b><span style="font-family:""><span style="font-family:Verdana;"> Tuberculosis is a heal...<b><span style="font-family:Verdana;">Background:</span></b><span style="font-family:""><span style="font-family:Verdana;"> Tuberculosis is a health problem in Sudan and may become a greater challenge in the future due to the weakness in infection prevention measures, increase in cases of drug-resistant and the difficulty of diagnosis.</span><b><span style="font-family:Verdana;"> Objective: </span></b><span style="font-family:Verdana;">The aim of this study was to detect </span><i><span style="font-family:Verdana;">Mycobacterium tuberculosis</span></i><span style="font-family:Verdana;"> (MTB) from sputum of clinically suspected patients using the three available techniques.</span><b><span style="font-family:Verdana;"> Methods:</span></b><span style="font-family:Verdana;"> Three</span><b> </b><span style="font-family:Verdana;">hundred participants referred to Wad Madani Tuberculosis Center during 2017-2019 were included. Early morning fresh sputum samples were subjected to </span><i><span style="font-family:Verdana;">Mycobacterium tuberculosis</span></i><span style="font-family:Verdana;"> examination by Ziehl-Neelsen</span><b> </b><span style="font-family:Verdana;">(ZN) stain without concentration, ZN stain with centrifugation and geneXpert assay. </span><b><span style="font-family:Verdana;">Results: </span></b><span style="font-family:Verdana;">Of the 300 suspected cases;</span><i><span style="font-family:Verdana;">Mycobacterium tuberculosis </span></i><span style="font-family:Verdana;">detected in 17% (51/300) by ZN stain</span><b> </b><span style="font-family:Verdana;">without concentration, 20% (59/300) by ZN stain with centrifugation and 34% (103/300) by geneXpert. The two techniques of ZN stains possessed 100% specificity and relative differences in sensitivity when compared to geneXpert assay. The significant association observed between ZN stains and geneXpert results indicated validity of ZN techniques for detection. </span><b><span style="font-family:Verdana;">Conclusions:</span></b><i> </i><span style="font-family:Verdana;">The study confirmed that geneXpert is better for identification of </span><i><span style="font-family:Verdana;">Mycobacterium</span></i> <i><span style="font-family:Verdana;">tuberculosis </span></i><span style="font-family:Verdana;">when compared to ZN techniques which are also important for diagnosis in poor places and where the geneXpert assay is not available.展开更多
文摘Microscopy-positive and drug-resistant pulmonary tuberculosis (MPT+) is one of the most feared diseases due to the cost of its management and the associated mortality. The GeneXpert, a new molecular test, is in greater demand for the diagnosis of MPT+ resistance cases. The application of GeneXpert to new cases of MPT+ is not effective in the country’s TB screening centres. The objective of this study is to assess the contribution of GeneXpert to the determination of MPT+ resistance cases in Bangui. The study was cross-sectional and covered the period from February to July 2022. The diagnosis of tuberculosis was first performed by microscopy with Ziehl Neelsen hot stain. The GeneXpert was then used to test for resistance in the sputum of all patients with positive microscopy. The collected data was entered into Excel 2013 and analysed with Epi Info 3.3.7. We analysed data from 755 patients, 80 of whom had resistance. The 80 patients ranged in age from 6 to 68 years (mean age = 35 years). The prevalence of resistant TB was 10.60% (80/755). Primary resistance accounted for 73.75% and secondary resistance for 26.25%. The age group 20 - 39 years (57.50%), male (72.50%), 8th district (17.50%), people living in couples (53.75%), farmers (13.75%) were the socio-demographic characteristics most affected by resistance. Treatment failure (13.75%), relapses (13.75%), the notion of contagion (28.75%), a history of smoking (40%) and alcohol (61.25%) were the clinical antecedents reported by the patients. Treatment failure and relapse were the variables associated with the occurrence of resistant PMT+ (p 0.05). A considerable proportion of the overall Mycobacterium tuberculosis resistance to anti-tuberculosis drugs (10.60%) was identified by GeneXpert. Treatment failure and relapse were the factors associated with the risk of resistance.
文摘Detection of Mycobacterium tuberculosis complex (MTBC) in extrapulmonary specimens can be challenging due to their paucibacillary nature. This difficulty is especially true for cerebrospinal fluid (CSF), and the low sensitivity and specificity for diagnosis hampers rapid detection and treatment in vulnerable populations. GeneXpert MTB/RIF Ultra has been shown to provide rapid results for detection of MTBC and associated Rifampin resistance, but there is limited data regarding standardized methods for CSF processing on this assay. In this study, we sought to provide guidance regarding the best methods for CSF processing, including optimal volumes to test, length of incubation with sample reagent and finally effects of long-term freezing on detection.
基金funded by the projects 2013ZX10003002-001 and 2013ZX10003006-002-001 of Chinese National Key Program of Mega Infectious Disease of the National 12th Five-Year Plan
文摘Objective A PCR-reverse dot blot hybridization （RDBH） assay was developed for rapid detection of rpoB gene mutations in ＇hot mutation region＇ of Mycobacterium tuberculosis （M. tuberculosis）. Methods 12 oligonucleotide probes based on the wild-type and mutant genotype rpoB sequences of M. tuberculosis were designed to screen the most frequent wild-type and mutant genotypes for diagnosing RIF resistance. 300 M. tuberculosis clinical isolates were detected by RDBH, conventional drug-susceptibility testing （DST） and DNA sequencing to evaluate the RDBH assay. Results The sensitivity and specificity of the RDBH assay were 91.2% （165/181） and 98.3% （117/119）, respectively, as compared to DST. When compared with DNA sequencing, the accuracy, positive predictive value （PPV） and negative predictive value （NPV） of the RDBH assay were 97.7% （293/300）, 98.2% （164/167）, and 97.0% （129/133）, respectively. Furthermore, the results indicated that the most common mutations were in codons 531 （48.6%）, 526 （25.4%）, 516 （8.8%）, and 511 （6.6%）, and the combinative mutation rate was 15 （8.3%）. One and two strains of insertion and deletion were found among all strains, respectively. Conclusion Our findings demonstrate that the RDBH assay is a rapid, simple and sensitive method for diagnosing RIF-resistant tuberculosis.
文摘Objective:To identify the clinical,laboratory,and radiological markers that could predict a positive GeneXpert result in patients suspected of tuberculous meningitis.Methods:In this prospective,observational study,patients with tuberculous meningitis were systematically evaluated.Various clinical,laboratory[including cerebrospinal fluid(CSF)microscopy,culture,and GeneXpert],and neuroimaging factors were examined.All participants were administered anti-tuberculous treatment and corticosteroids.A six-month follow-up was done to evaluate the outcome.Results:Of the 116 patients studied,54(46.6%)tested positive for GeneXpert,while 62(53.4%)were negative.Third cranial nerve involvement(OR 3.71,95%CI 1.052-13.09,P=0.04)and the presence of basal exudates on neuroimaging(OR 5.22,95%CI 2.03-13.42,P=0.001)emerged as independent predictive factors for a positive GeneXpert result.A positive CSF GeneXpert result(P=0.002)and drug resistance(P=0.004)were significantly linked to adverse outcomes.Additionally,a high score on the Medical Research Council stageⅢ(OR 5.64,95%CI 1.18-26.87,P=0.03)and elevated CSF cell counts(OR 1.002,95%CI 1.00-1.001,P=0.03)were identified as independent predictors of poor prognosis.Conclusions:Third cranial nerve involvement and the presence of basal exudates were significant indicators of a positive GeneXpert result.MRC stageⅢdisability and elevated CSF cell counts predicted poor outcomes.
基金supported by the grant from the National Natural Science Foundation of China (No. 30400018)
文摘Objective To detect the specific mutations in rpoB gene of Mycobacterium tuberculosis by oligonucleotide microarray. Methods Four wild-type and 8 mutant probes were used to detect rifampin resistant strains. Target DNA of M. tuberculosis was amplified by PCR, hybridized and scanned. Direct sequencing was performed to verify the results of oligonucleotide microarray Results Of the 102 rifampin-resistant strains 98 （96.1%） had mutations in the rpoB genes. Conclusion Oligonucleotide microarray with mutation-specific probes is a reliable and useful tool for the rapid and accurate diagnosis of rifampin resistance in M. tuberculosis isolates.
文摘<b><span style="font-family:Verdana;">Background:</span></b><span style="font-family:""><span style="font-family:Verdana;"> Tuberculosis is a health problem in Sudan and may become a greater challenge in the future due to the weakness in infection prevention measures, increase in cases of drug-resistant and the difficulty of diagnosis.</span><b><span style="font-family:Verdana;"> Objective: </span></b><span style="font-family:Verdana;">The aim of this study was to detect </span><i><span style="font-family:Verdana;">Mycobacterium tuberculosis</span></i><span style="font-family:Verdana;"> (MTB) from sputum of clinically suspected patients using the three available techniques.</span><b><span style="font-family:Verdana;"> Methods:</span></b><span style="font-family:Verdana;"> Three</span><b> </b><span style="font-family:Verdana;">hundred participants referred to Wad Madani Tuberculosis Center during 2017-2019 were included. Early morning fresh sputum samples were subjected to </span><i><span style="font-family:Verdana;">Mycobacterium tuberculosis</span></i><span style="font-family:Verdana;"> examination by Ziehl-Neelsen</span><b> </b><span style="font-family:Verdana;">(ZN) stain without concentration, ZN stain with centrifugation and geneXpert assay. </span><b><span style="font-family:Verdana;">Results: </span></b><span style="font-family:Verdana;">Of the 300 suspected cases;</span><i><span style="font-family:Verdana;">Mycobacterium tuberculosis </span></i><span style="font-family:Verdana;">detected in 17% (51/300) by ZN stain</span><b> </b><span style="font-family:Verdana;">without concentration, 20% (59/300) by ZN stain with centrifugation and 34% (103/300) by geneXpert. The two techniques of ZN stains possessed 100% specificity and relative differences in sensitivity when compared to geneXpert assay. The significant association observed between ZN stains and geneXpert results indicated validity of ZN techniques for detection. </span><b><span style="font-family:Verdana;">Conclusions:</span></b><i> </i><span style="font-family:Verdana;">The study confirmed that geneXpert is better for identification of </span><i><span style="font-family:Verdana;">Mycobacterium</span></i> <i><span style="font-family:Verdana;">tuberculosis </span></i><span style="font-family:Verdana;">when compared to ZN techniques which are also important for diagnosis in poor places and where the geneXpert assay is not available.
